1. Field of the Invention
The invention relates to a non-migrating, directional radiographic marker for an indicating the position and entry direction of a biopsy site.
2. Brief Description of the Prior Art
In many cases it is necessary for a surgeon to localize a portion of tissue or foreign matter in the tissue that is to be removed in an operative procedure. The localization of tissue also occurs during biopsies wherein the location of the biopsy tissue must be reproducible in the event further biopsy or surgery is required. To facilitate the location of the tissue or foreign matter, markers are temporarily inserted into the tissue at the required location. Problems have occurred when a needle biopsy of a breast lesion is performed and the radiographic evidence of the breast lesion is either distorted or inadvertently removed. When needle biopsy pathology shows carcinoma, further localization must be accomplished to surgically excise the entire cancer. If radiographic evidence of the lesion is no long well defined or is no longer present, subsequent localization is problematic.
One prior art method is the use of a hypodermic needle placed into the breast to location the lesion. When the needle is properly placed, a stainless steel wire having a hairpin hooked-end portion is slide through the needle to engage the body tissue, thereby retaining the needle adjacent to or at the breast lesion. The hypodermic needle is withdrawn over the wire and the wire anchored until after surgery. However, the compression of the breast during mammographic filming and situation of the needle can cause the needle to move or be displaced with respect to the breast lesion. U.S. Pat. No. 4,592,356 discloses the use of a localization device having a needle with an anchoring device at a distal end to firmly anchor the needle into the tissue. A clamping device is provided at the proximal end to anchor the needle to the skin. The rigid needle keeps the barbs and needle in place until removal.
U.S. Pat. No. 5,127,916 discloses a localization needle that is readily positioned and locked within body tissue to locate pinpoint lesions. The '916 device utilizes a barb to lodge the marker within the tissue. In U.S. Pat. No. 5,158,565 a hollow needle hub is used to anchor the proximal end of a barbed stylet and releasably retains the surrounding needle for movement from a sheathing position for the barb to a position projecting the barb outside the needle. The hub is a one-piece split body resiliently closed and expanded by a surgeon's action to release the cannula or hollow needle for sliding movement to retract or expose the barb.
U.S. Pat. No. 5,853,366 discloses a two and three legged V-shaped resilient member that is capable of being positioned wholly within the body of a patient. The resiliency of the legs of the V-shape enables the marker to collapse to a reduced size while be inserted along the hollow dispenser, resuming its original V-shape upon discharge from the guide member. Neither of the embodiments, however, provide any method of anchoring the device within the tissue. Further, as the third leg is design approximately parallel with the other two legs, there is nothing to prevent the device from flattening or rotating. Once the legs, whether there are two or three, flatten, the marking device becomes a linear bar, rendering it impossible to know where it was pointing upon its initial positioning.
A Lesion Location Device is described in U.S. Pat. No. 5,059,197 that uses a wire bent at a 180 degree angle, forming a first and second portion. A third portion extends adjacent the second portion and continues beyond the bend in a direction substantially opposed to the second portion. The pivotable bend forms a spring mechanism to prevent ingress of the wire once placed.
U.S. Pat. No. 5,800,445 discloses a Tissue Tagging Device for marking the location of lesions. This marking device, in its main embodiment, utilizes a wire marker that is inserted through an elongated tube. Another embodiment includes an arcuate anchor in addition to the wire marker.
As can be seen, prior art marking devices include straight, curved or helical coil markers, however these do not necessarily point to the exact approach taken to obtain the biopsy. Check-mark shaped indicators and act like porcupine quills and ratchet through the tissue with movement, thus being susceptible to migration within the tissue. V-shaped coils can flatten with time and straighten or distort, thereby eliminating the exact approach area. Additionally, the hooks used in the prior art are internally "anchored" within the fatty tissue within the breast, which does not always provide sufficient anchoring and/or stability to the hook-wire combination.
The prior art devices also address predominately marking lesions for surgery, not the time span between biopsies or biopsy to surgery. Most of the prior art devices cannot be left in the patients body to serve as a marker for future procedures, but rather are removed within a short period of insertion.
The disclosed device overcomes the prior art problems by inserting a small marker device through the biopsy needle at the time of biopsy, thereby providing a radiographic target for future localization in the event of surgery.